package com.cainaer.common.core.utils;

import com.alibaba.fastjson.JSONObject;
import com.cainaer.common.core.utils.sign.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.springframework.beans.factory.annotation.Value;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.AlgorithmParameters;
import java.security.Security;
import java.util.Arrays;

/**
 * @author Tina
 * @version 1.0
 * @date 2020/8/26 下午3:03
 * <p>
 * 微信工具类
 *
 * BUG-> 无法从公共yml配置文件读取到数据
 *
 * @Value("${wx.APP_ID}") private String appId;
 * @Value("${wx.SECRET_KEY}") private String secretKey;
 * @Value("${wx.MP_LOGIN_URL}") private String mpLoginUrl;
 * @Value("${wx.APP_ID}") public void setAppId(String appId) {
 * WxUtil.APP_ID = appId;
 * }
 * @Value("${wx.SECRET_KEY}") public void setSecretKey(String secretKey) {
 * WxUtil.SECRET_KEY = secretKey;
 * }
 * @Value("${wx.MP_LOGIN_URL}") public void setMpLoginUrl(String mpLoginUrl) {
 * WxUtil.MP_LOGIN_URL = mpLoginUrl;
 * }
 **/
public class WxUtil {

    public static String APP_ID="wx9bee97e9b898dbd8";

    public static String SECRET_KEY="009666ca0e89599144ed019682514175";

    public static String MP_LOGIN_URL="https://api.weixin.qq.com/sns/jscode2session";


    public static JSONObject getUserInfo(String encryptedData, String sessionKey, String iv) {
        // 被加密的数据
        byte[] dataByte = Base64.decode(encryptedData);
        // 加密秘钥
        byte[] keyByte = Base64.decode(sessionKey);
        // 偏移量
        byte[] ivByte = Base64.decode(iv);

        try {
            // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                return JSONObject.parseObject(result);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}
